Drill



W. C. REA

Jan. 16, 1934.,

Filed May 8. 1930 ATTORN EY I Patented Jan. 16, 1934 DRILL Walter C. Rea, New York, N. Y., as'signor to Detachable Bit Corporation of America, New York, N. Y., a corporation of Delaware Application May 8, 1930. Serial No. 450,629

11 Claims. (Cl. 255-64) This invention relates to drills, such as those used for drilling rock, which have passages extending lengthwise thereof for conveying air or water, and particularly to the type wherein a bit I is detachably secured to a drill rod; and its principal object resides in the provision of a novel drill construction which is simple and. inexpensive to manufacture, rugged and durable in service, and eflicient in operation.

Heretofore, it has been the practise to have the passage for air or water located centrally of the drill rod and bit. I have now found that, by constructing the drill so that there is a groove along the side of the bit or a passage between the bit and the member which secures it to the rod,

communicating with the passage in the rod, nu-

merous advantages are achieved, among which are simplicity in the machining operations, better hardening of the part; and greater strength due to the presence of more solid metal.

The invention will be described with reference to constructions disclosed in my copending applications, Serial Nos. 442,495, 442,496 and 442,497, filed April 8, 1930, but it is not to be construed as restricted to use in connection with the specific coupling means illustrated. Reference is had to the accompanying drawing, wherein:

Fig.-1 is a vertical section through the center of a preferred form of assembled drill rod and bit in accordance with the present invention. Fig. 2 is an end view of the construction shown in Fig. 1, looking upward from below. Fig. 3 is a side elevation of the bit as viewed when turned at 90 from its position in Fig. 1. Fig. 4 is a vertical, central section through a modified form of drill construction. Fig. 5 is a section taken on the line 55 of Fig. 4, looking down. Fig. 6 is an elevation of the central member of Fig. 4 at 90 to its position therein.

In the preferred form of my invention as illustrated in Figs. 1, 2 and 3, there is shown at 1 the end of a drill rod having acentral passage 2 formed therein. A bit 3, having'cutting edges 4, is formed with threads 5. This bit may be coupled to the drill rod by means of a coupling member 6 having internal threads '1 and 8 for engagement respectively, with threads 9 on the rod and threads 5 on the bit. The rod and bit are formed with shoulders 10 and 11 respectively and the coupling member is provided with a flange 12 adapted to lie within the space formed by these shoulders when the parts are assembled, and is of such size that it is permitted to travel a predetermined distance to abut against one or the other of the shoulders. By means of this construction, the face 13 of the bit abut-s directly against the face 14 of the rod, thus relieving the coupling of substantially all of the impact forces.

Extending along one side of the bit, there is formed a groove 15 which communicates at, its upper end with another groove 16 which is substantially at right angles to the first groove and extends inward to such a distance that it communicates with the passage 2 of the drill rod, thereby forming a continuous passage for water, air or other fluid which is delivered through the passage 2.

By this construction, it is possible to provide a bit with cutting edges which extend across the full diameters of the bit. In addition to the advantages enumerated above, this construction has the very important function of eliminating wedging of solid material in the fluid passage. It so happens that after operating a .bit having a central passage, it is often necessary to make use of a punch to drive out pieces of rock and other material which have lodged in the passage. Not only is this a disadvantage, but the use of the punch often leads to the formation of rough projections in the interior of the passage, so that there is an even greater tendency for pieces of stone and so forth to become wedged against the sides of the passage and to be held byv these proj ections. In this event, the air which is commonly used to blow out the particles is of no effect. It will be appreciated that in the present construction, there is little or no chance of particles becoming wedged, because they can simply fall back between the cutting edges of the drill (see Fig. 1)

Another advantage of this construction is that the cutting edges may be continued fully across the bit and thus give an unbroken drilling surface at the points where it is most needed, the fluid being delivered by the groove 15 between the cutting edges.

Turning now to Figs. 4, 5 and 6, there is shown at 21 a drill rod having a passage 22 formed therein. The rod is formed with an opening 23 which is internally threaded as at 24 and shouldered as at 25. The bit 26 has an opening 2'7 therein similarly threaded as at 28 and shouldered as at 29. For securing the bit to the drill rod there is provided a coupling member 30, having threads 31 and 32 for engagement respectively with the threads of the rod and bit, and having a flange 33 which lies within the shouldered portions and is of such dimensions that it is permitted to ride up and down a predetermined distance to abut against one or the other of the shoulders.

slightly smaller diameter than the opening, but of course, it may fit snugly therewith. A groove 34 extends along the side of the coupling member the full length thereof. This groove serves to carry the fluid which is delivered through the passage 22. The coupling member is so proportioned that it can never abut against the top of the opening 23 and thus there is always a continuous passage from the rod to the drilling surface. The coupling member may be provided with an auxiliary cutting edge 35.

While I have described preferred embodiments of my invention in detail, the invention is not to be limited save by the scope of the appended claims.

What I claim as new is:

1. In a device of the class described, the combination of a drill rod having a passageway extending axially therethrough and having one end of the passageway twice enlarged, the first enlargement being threaded and the second enlargement being smooth and forming a stop shoulder, a bit engaging the end of the rod which has the smooth enlargement to form a percussion transferring joint therebetween, said bit provided with an opening extending therethrough with the end adjacent the drill rod enlarged and smooth and the other end being threaded, a coupling member having its opposite ends in threaded engagement with the threaded parts of the drill rod and bit and provided with a stop flange extending into the smooth enlargements at the joint between the drill rod and bit, said coupling member provided with a groove extending along one side thereof from end to end and across said flange, the end of the coupling member which is intruded into the drill rod being spaced from the adjacent end of the first enlargement to form a transverse opening for placing one end of the groove in fluid communication with the unenlarged part of the passageway in the drill rod, and said flange in its engagement with the stop shoulder acting to prevent the coupling member from moving int position to close said transverse opening.

2. In a device of the class described, the combination of a drill rod provided with a passageway extending axially therethrough and being twice enlarged at one end, the first enlargement being threaded and the second enlargement providing a stop shoulder, a coupling member intruded into the enlarged end of the passageway and having one end in screw threaded engagement with the threaded first enlargement and having its other provided with means for engaging a bit, the intruded end of the coupling member being spaced from the adjacent end of the first enlargement to form a transverse fiuiding conducting opening in permanent fluid communication with the passageway, said coupling member provided with a grove extending along one side and open at one end to the transverse opening and said coupling provided with a flange disposed in the second enlargement and restrained from movement by the stop shoulder to prevent the coupling member from closing the transverse opening.

3. In a device of the class described, the combination of a bit having a main cutting edge at one end and provided with an opening extending axially therethrough. an externally threaded coupling member extending through the opening in threaded engagement with the bit and provided with an auxiliary cutting edge coacting with the main outing edge of the bit to form in efiect a two-part bit, said coupling member provided on one side with a fluid conducting groove coacting with the bit to form a passageway for discharging fluid directly to the cutting edges at a point between the main and auxiliary cutting edges and said coupling member including a threaded portion projecting from the bit and adapted for threaded engagement with a drill rod and said groove extending from the bit along said projecting threaded portion.

4. In a device of the class described, the combination of a bithaving a main cutting edge at one end and provided with an opening extending axially therethrough, an externally threaded coupling member extending through the opening in threaded engagement with the bit and provided with an auxiliary cutting edge coacting with the main cutting edge of the bit to form in efiect a two-part bit, said coupling member provided on one side with a fluid conducting groove coacting With the bit to form a passageway for discharging fluid directly to the outing edges at a point between the main and auxiliary cutting edges.

5. In a drill, the combination of three readily detachable parts forming the active end of a drill, said parts comprising a drill rod provided with an axially extending passage enlarged adjacent one end and internally threaded, a bit having a cutting edge at one end and with its opposite end engaging the rod and said bit provided with an opening extending therethrough and internally threaded, and a preformed, male coupling member having opposite ends externally threaded and in threaded engagement with the rod and bit, and said coupling member provided along one side with a groove extending from end to end and coacting with the bit and drill rod to provide a fluid conducting pasageway extending from the passage in the drill rod to the cutting edge of the bit and discharging adjacent the center of the cutting edges of the bit.

6. In a device of the class described, the combination of a drill rod internally threaded and provided with a fluid passageway internally.

threaded, a bit provided with a bore extending axially therethrough and internally threaded and having cutting edges formed on one end, a male coupling member solid from end to end along its axis, having its opposite ends in threaded engagement with the threads on the drill rod and bit and said coupling member provided with a groove extending longitudinally along one side and from end to end coacting with the bit and drill rod to form a fluid passageway having one end in connection with the passageway in the drill rod and discharging through the cutting edge forming end of the bit adjacent the axis of rotation of the bit.

7. A drill bit provided with an internally threaded bore, an externally threaded coupling member having one end in threaded engagement with the bore and said bit adapted to be screwed on and off the end of the coupling member, said coupling member provided on one side with a long groove coacting with the bore to form a fluid passageway through the bit and otherwise of solid rugged construction along the length of its axis.

8. A drill coupling having opposite ends externally threaded for engaging with a bit and drill rod provided with a stop flange the threaded ends being of substantially long cylindrical form and the stop flange being of substantially short cylindrical form, with a diameter greater than the threaded ends and presenting flat parallel surfaces on opposite sides thereof extending perpendicular to the axis of the coupling, and with a fluid conducting groove extending from end to end of the coupling and across the flange.

9. In a percussively driven rock drill, the combination of a tubular drill rod and bit in end to end abutting relation and with their bores providing fluid passageways, and a male coupling member solid along the axis of rotation of the drill having opposite ends inthreaded engagement with the rod and bit and provided on one side with along straight groove coacting along its entire length with the bore through the bit for transmitting fluids from the bore of the drill rod through the bit in spaced relation within the outline of its cutting edges.

10. In a device of the class described, the combination of a bit having a bore extending axially therethrough and provided at one end with a cutting edge intercepted by the bore in the bit, a supplemental cutter member having one end intruded into the bore and provided at the intruded end with a cuttingedge adapted to be disposed substantially in the plane of the cutting edge of the bit and in position to fill in the gap between the cutting edge on the bit and thus continue the cutting edge acrossthe full diameter of the bit and a channel extending along the side of the supplemental cutter for supplying a fluid to the cutting edge between its center and one of its ends.

11. In a rotary impact drill, the combination of two tubular sections in end to end abutting relation, said sections providing opposed shoulder stops with a recess therebetween, a coupling having opposite ends in threaded engagement with the sections and having a flange disposed in said recess between said stops spaced from one of the stops and coacting with the stops to limit the movement of the coupling relative 'to the sections and said coupling provided with a groove on one side thereof extending across the flange and coacting with the sections to provide a passageway from one to the other end of the coupling.

WALTER C. REA. 

